Green-function approach to transport through a gate-surrounded Si nanowire with impurity scattering

We investigate the transport properties of gate-surrounded Si nanowires using a nonequilibrium Green's function technique. By taking into account the ionized-impurity scattering, we calculate Green's functions self-consistently and examine the effects of ionized-impurity scattering on the electron densities and the currents. For nanoscale Si wires, it is found that, due to the impurity scattering, the local density of state profiles lose its interference oscillations as well as is broadened and shifted. In addition, the impurity scattering gives rise to a different transconductance as a function of temperature and impurity scattering strength when compared with that in the absence of impurity scattering.